Heres the variance of the 30 degree to 55 degree change of temperature along with the 5000 feet elevation up to 10000 feet change.

At 50 degrees and 5000 feet elevation at 1000 yards, I would need 16.1 MOA in my 338/416 Rigby

At 30 Degrees and 10,000 feet elevation at 1000 yards, I would need 15.4 MOA to cover the same distance.

We are talking about 7/10 MOA or 7" at 1000 yards.

Not really a MAJOR concern if your spotting for someone or have a spotter for you.

This would change though if someone were shooting a bullet of low BC as compared to what mine does.

As for the ballsitics program.
I was refering to the small computers that are available and not to a tiny little hand held. Some of the very small laps that you can hardly use the small keys would work for you.

WW,
The Horus Vision has a Handspring Visor and a chip loaded with a program capable of what we need, including angle changes, wind, BP, Temp etc. $240.00 for everything. I talked to Dick B. over there and this is the model we need for use in the field he says. Used with any other palm device, the program is lost when the batteries go dead. It then needs to be reloaded while connected to a laptop or desktop PC containing it too. This is not necessary with the Handspring Visor unit, it contains the info on the chip so new batteries just need to be installed then turned back on.

I'll be getting one in a couple weeks and will let everyone know how it works out.